This application claims the priority benefit under 35 U.S.C. § 119 of Japanese Patent Application No. 2005-352881 filed on Dec. 7, 2005, which is hereby incorporated in its entirety by reference.
1. Field
The disclosed subject matter relates to a vehicle light such as a vehicle headlight, a vehicle auxiliary light, spot light, traffic light, and the like, having a reflector for reflecting light emitted from a light source and another reflector for reflecting the reflected light in front of the vehicle (e.g., along an light emitting direction of the vehicle light). In particular, the disclosed subject matter relates to a vehicle light which can reduce the difference between the cut-off line of the actual light distribution pattern and the cut-off line of the designed light distribution pattern. Furthermore, the disclosed subject matter relates to a vehicle light in which a reflector for reflecting light emitted from a light source can be processed easily and which can reduce the abovementioned difference between the cut-off line of the actual light distribution pattern and the cut-off line of the designed light distribution pattern.
2. Description of the Related Art
FIG. 1 is a perspective view showing a conventional vehicle light formed as a headlight. In FIG. 1, reference numeral 101 denotes a light source such as a filament coil for a light source, or a high light intensity part of a discharge lamp. Reference numeral 102 denotes a bulb containing the light source 101, and reference numeral 103 denotes a socket hole through which the bulb 102 is mounted. Reference numeral 104 denotes a reflector for reflecting light from the light source 101 in front of the vehicle. The surface of the reflector 104 is formed as a single complex reflecting surface extending in the right and left direction. Another type of reflector for a vehicle headlight includes a conventional multi-reflector (not shown) having a plurality of reflecting surfaces. Before developing such a multi-reflector for a vehicle headlight, a revolved parabolic surface had been mainly adopted as the reflecting surface of a vehicle headlight.
In FIG. 1, reference numeral 105 denotes a cover lens (or a front lens), and reference numeral 106 denotes a grouped lens composed of a plurality of ribbed lenses arranged on the center part of the cover lens 105. The shown conventional vehicle headlight has the grouped lens 106 only on the center part of the cover lens 105, but a vehicle headlight having a grouped lens 106 formed over a cover lens 105 has been conventionally known (not shown). Further, the grouped lens 106 may be separately formed from the cover lens 105 and may be arranged inside the cover lens 105 (not shown).
Reference numeral 107 denotes a metal cover for shielding direct light from the light source 101 that is directed toward the outside to prevent light from becoming glare light which is outside the specifications or regulations for the given lamp. Another conventional vehicle headlight has been known which has another grouped lens instead of such a metal cover 107, for preventing the direct light from the light source 101 from becoming glare light.
In the conventional vehicle headlight shown in FIG. 1, a light loss percentage of typically 10 to 20% typically occurs due to the provision of the grouped lens 106 that includes lens cuts. The main purpose of the lens cut is to produce diffusion light rightward and leftward. When the lens cut is provided to irradiate diffusion light rightward and leftward with an angle of 30° in the front-to-rear direction of the vehicle, light will inevitably attenuate. In addition to this, diffusion light that is spread rightward and leftward with an angle of 30° or greater (for example 40° to 50°) in the front-to-rear direction of the vehicle will not be increased, resulting in a darkened light.
On the other hand, still another type of conventional vehicle headlight has been known, which includes a light source, an elliptic reflector for reflecting light emitted from the light source, and a parabolic reflector for reflecting the light reflected from the elliptic reflector in front of the vehicle. Such a vehicle headlight is disclosed in Japanese Patent Laid-Open Publication No. 2002-313112, the disclosure of which is hereby incorporated in its entirety by reference.
This conventional vehicle headlight has elliptic reflectors on the respective right and left sides of the light source. They are disposed such that both the first foci thereof are located at the position of the light source. Furthermore, parabolic reflectors are disposed on the respective right and left sides of the light source to reflect light reflected from the respective right and left elliptic reflectors in front of the vehicle. In this instance, the focus of the left parabolic reflector is disposed in the vicinity of the position of the second focus of the right elliptic reflector while the focus of the right parabolic reflector is disposed in the vicinity of the position of the second focus of the left elliptic reflector. Furthermore, an opening is formed in the left elliptic reflector in order to guide light reflected by the right elliptic reflector towards the left parabolic reflector, and vice versa.
Furthermore, in this vehicle headlight, the edge portions of the openings in the right and left elliptic reflectors are designed such that cut-off lines are formed in the light distribution patterns irradiated in front of the vehicle by the respective right and left parabolic reflectors.
In a vehicle headlight as disclosed in Japanese Patent Laid-Open Publication No. 2002-313112, the light source is covered with the right and left elliptic reflectors. The portion for supporting the light source and the right and left elliptic reflectors are typically formed as separate members. This facilitates the processing of the right and left elliptic reflectors.
In such a configuration where the support portion and the right and left elliptic reflectors are separately formed, the cut-off line of the light distribution pattern formed by the edge portion of the opening of the right elliptic reflector may be deviated from the cut-off line of the designed light distribution pattern. This is true in the case of the left elliptic reflector. It is conceivable that this may be caused by manufacturing errors of the support member and the elliptic reflectors, and assembly errors of the elliptic reflectors with respect to the support member. The presently disclosed subject matter results from earnest research into a technique for reducing the effect of the errors that appear due to the actual cut-off line being shifted from the designed cut-off line.
In view of the abovementioned and other conventional problems, it has been found that the edge portion, which forms the cut-off line of the light distribution pattern, can be removed from the right and left elliptic reflectors, and instead can be provided in a support portion for supporting a light source. This configuration can reduce the difference between the cut-off line of the actual light distribution pattern and the cut-off line of the designed light distribution pattern.